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<div class="refentry">
<a name="SpicePlaybackChannel"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle"><a name="SpicePlaybackChannel.top_of_page"></a>Playback Channel</span></h2>
<p>Playback Channel — audio stream for playback</p>
</td>
<td class="gallery_image" valign="top" align="right"></td>
</tr></table></div>
<div class="refsect1">
<a name="SpicePlaybackChannel.stability-level"></a><h2>Stability Level</h2>
<acronym title="The intention of a Stable interface is to enable arbitrary third parties to
develop applications to these interfaces, release them, and have confidence that
they will run on all minor releases of the product (after the one in which the
interface was introduced, and within the same major release). Even at a major
release, incompatible changes are expected to be rare, and to have strong
justifications.
"><span class="acronym">Stable</span></acronym>, unless otherwise indicated
</div>
<div class="refsect1">
<a name="SpicePlaybackChannel.functions"></a><h2>Functions</h2>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="functions_return">
<col class="functions_name">
</colgroup>
<tbody><tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="SpicePlaybackChannel.html#spice-playback-channel-set-delay" title="spice_playback_channel_set_delay ()">spice_playback_channel_set_delay</a> <span class="c_punctuation">()</span>
</td>
</tr></tbody>
</table></div>
</div>
<div class="refsect1">
<a name="SpicePlaybackChannel.properties"></a><h2>Properties</h2>
<div class="informaltable"><table border="0">
<colgroup>
<col width="150px" class="properties_type">
<col width="300px" class="properties_name">
<col width="200px" class="properties_flags">
</colgroup>
<tbody>
<tr>
<td class="property_type"><span class="type">guint</span></td>
<td class="property_name"><a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannel--min-latency" title="The “min-latency” property">min-latency</a></td>
<td class="property_flags">Read / Write</td>
</tr>
<tr>
<td class="property_type"><span class="type">gboolean</span></td>
<td class="property_name"><a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannel--mute" title="The “mute” property">mute</a></td>
<td class="property_flags">Read / Write</td>
</tr>
<tr>
<td class="property_type"><span class="type">guint</span></td>
<td class="property_name"><a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannel--nchannels" title="The “nchannels” property">nchannels</a></td>
<td class="property_flags">Read / Write</td>
</tr>
<tr>
<td class="property_type"><span class="type">gpointer</span></td>
<td class="property_name"><a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannel--volume" title="The “volume” property">volume</a></td>
<td class="property_flags">Read / Write</td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="SpicePlaybackChannel.signals"></a><h2>Signals</h2>
<div class="informaltable"><table border="0">
<colgroup>
<col width="150px" class="signals_return">
<col width="300px" class="signals_name">
<col width="200px" class="signals_flags">
</colgroup>
<tbody>
<tr>
<td class="signal_type"><span class="returnvalue">void</span></td>
<td class="signal_name"><a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannel-playback-data" title="The “playback-data” signal">playback-data</a></td>
<td class="signal_flags">Run First</td>
</tr>
<tr>
<td class="signal_type"><span class="returnvalue">void</span></td>
<td class="signal_name"><a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannel-playback-get-delay" title="The “playback-get-delay” signal">playback-get-delay</a></td>
<td class="signal_flags">Run First</td>
</tr>
<tr>
<td class="signal_type"><span class="returnvalue">void</span></td>
<td class="signal_name"><a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannel-playback-start" title="The “playback-start” signal">playback-start</a></td>
<td class="signal_flags">Run First</td>
</tr>
<tr>
<td class="signal_type"><span class="returnvalue">void</span></td>
<td class="signal_name"><a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannel-playback-stop" title="The “playback-stop” signal">playback-stop</a></td>
<td class="signal_flags">Run First</td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="SpicePlaybackChannel.other"></a><h2>Types and Values</h2>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="name">
<col class="description">
</colgroup>
<tbody>
<tr>
<td class="datatype_keyword">struct</td>
<td class="function_name"><a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannel-struct" title="struct SpicePlaybackChannel">SpicePlaybackChannel</a></td>
</tr>
<tr>
<td class="datatype_keyword">struct</td>
<td class="function_name"><a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannelClass" title="struct SpicePlaybackChannelClass">SpicePlaybackChannelClass</a></td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="SpicePlaybackChannel.object-hierarchy"></a><h2>Object Hierarchy</h2>
<pre class="screen">    GObject
    <span class="lineart">╰──</span> <a class="link" href="SpiceChannel.html" title="Spice Channel">SpiceChannel</a>
        <span class="lineart">╰──</span> SpicePlaybackChannel
</pre>
</div>
<div class="refsect1">
<a name="SpicePlaybackChannel.includes"></a><h2>Includes</h2>
<pre class="synopsis">#include &lt;spice-client.h&gt;
</pre>
</div>
<div class="refsect1">
<a name="SpicePlaybackChannel.description"></a><h2>Description</h2>
<p><a class="link" href="SpicePlaybackChannel.html" title="Playback Channel"><span class="type">SpicePlaybackChannel</span></a> class handles an audio playback stream. The
audio data is received via <a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannel-playback-data" title="The “playback-data” signal"><span class="type">“playback-data”</span></a>
signal, and is controlled by the guest with
<a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannel-playback-stop" title="The “playback-stop” signal"><span class="type">“playback-stop”</span></a> and
<a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannel-playback-start" title="The “playback-start” signal"><span class="type">“playback-start”</span></a> signal events.</p>
<p>Note: You may be interested to let the <a class="link" href="SpiceAudio.html" title="Spice Audio"><span class="type">SpiceAudio</span></a> class play and
record audio channels for your application.</p>
</div>
<div class="refsect1">
<a name="SpicePlaybackChannel.functions_details"></a><h2>Functions</h2>
<div class="refsect2">
<a name="spice-playback-channel-set-delay"></a><h3>spice_playback_channel_set_delay ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
spice_playback_channel_set_delay (<em class="parameter"><code><a class="link" href="SpicePlaybackChannel.html" title="Playback Channel"><span class="type">SpicePlaybackChannel</span></a> *channel</code></em>,
                                  <em class="parameter"><code><span class="type">guint32</span> delay_ms</code></em>);</pre>
<p>Adjust the multimedia time according to the delay.</p>
<div class="refsect3">
<a name="id-1.2.3.8.11.2.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>channel</p></td>
<td class="parameter_description"><p>a <a class="link" href="SpicePlaybackChannel.html" title="Playback Channel"><span class="type">SpicePlaybackChannel</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>delay_ms</p></td>
<td class="parameter_description"><p>the delay in ms</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
</div>
<div class="refsect1">
<a name="SpicePlaybackChannel.other_details"></a><h2>Types and Values</h2>
<div class="refsect2">
<a name="SpicePlaybackChannel-struct"></a><h3>struct SpicePlaybackChannel</h3>
<pre class="programlisting">struct SpicePlaybackChannel;</pre>
<p>The <a class="link" href="SpicePlaybackChannel.html" title="Playback Channel"><span class="type">SpicePlaybackChannel</span></a> struct is opaque and should not be accessed directly.</p>
</div>
<hr>
<div class="refsect2">
<a name="SpicePlaybackChannelClass"></a><h3>struct SpicePlaybackChannelClass</h3>
<pre class="programlisting">struct SpicePlaybackChannelClass {
    SpiceChannelClass parent_class;

    /* signals */
    void (*playback_start)(SpicePlaybackChannel *channel,
                           gint format, gint channels, gint freq);
    void (*playback_data)(SpicePlaybackChannel *channel, gpointer *data, gint size);
    void (*playback_stop)(SpicePlaybackChannel *channel);
};
</pre>
<p>Class structure for <a class="link" href="SpicePlaybackChannel.html" title="Playback Channel"><span class="type">SpicePlaybackChannel</span></a>.</p>
<div class="refsect3">
<a name="id-1.2.3.8.12.3.5"></a><h4>Members</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="300px" class="struct_members_name">
<col class="struct_members_description">
<col width="200px" class="struct_members_annotations">
</colgroup>
<tbody>
<tr>
<td class="struct_member_name"><p><a class="link" href="SpiceChannel.html#SpiceChannelClass" title="SpiceChannelClass"><span class="type">SpiceChannelClass</span></a> <em class="structfield"><code><a name="SpicePlaybackChannelClass.parent-class"></a>parent_class</code></em>;</p></td>
<td class="struct_member_description"><p>Parent class.</p></td>
<td class="struct_member_annotations"> </td>
</tr>
<tr>
<td class="struct_member_name"><p><em class="structfield"><code><a name="SpicePlaybackChannelClass.playback-start"></a>playback_start</code></em> ()</p></td>
<td class="struct_member_description"><p>Signal class handler for the <a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannel-playback-start" title="The “playback-start” signal"><span class="type">“playback-start”</span></a> signal.</p></td>
<td class="struct_member_annotations"> </td>
</tr>
<tr>
<td class="struct_member_name"><p><em class="structfield"><code><a name="SpicePlaybackChannelClass.playback-data"></a>playback_data</code></em> ()</p></td>
<td class="struct_member_description"><p>Signal class handler for the <a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannel-playback-data" title="The “playback-data” signal"><span class="type">“playback-data”</span></a> signal.</p></td>
<td class="struct_member_annotations"> </td>
</tr>
<tr>
<td class="struct_member_name"><p><em class="structfield"><code><a name="SpicePlaybackChannelClass.playback-stop"></a>playback_stop</code></em> ()</p></td>
<td class="struct_member_description"><p>Signal class handler for the <a class="link" href="SpicePlaybackChannel.html#SpicePlaybackChannel-playback-stop" title="The “playback-stop” signal"><span class="type">“playback-stop”</span></a> signal.</p></td>
<td class="struct_member_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
</div>
<div class="refsect1">
<a name="SpicePlaybackChannel.property-details"></a><h2>Property Details</h2>
<div class="refsect2">
<a name="SpicePlaybackChannel--min-latency"></a><h3>The <code class="literal">“min-latency”</code> property</h3>
<pre class="programlisting">  “min-latency”              <span class="type">guint</span></pre>
<p>Playback min buffer size (ms).</p>
<p>Flags: Read / Write</p>
<p>Default value: 200</p>
</div>
<hr>
<div class="refsect2">
<a name="SpicePlaybackChannel--mute"></a><h3>The <code class="literal">“mute”</code> property</h3>
<pre class="programlisting">  “mute”                     <span class="type">gboolean</span></pre>
<p>Mute.</p>
<p>Flags: Read / Write</p>
<p>Default value: FALSE</p>
</div>
<hr>
<div class="refsect2">
<a name="SpicePlaybackChannel--nchannels"></a><h3>The <code class="literal">“nchannels”</code> property</h3>
<pre class="programlisting">  “nchannels”                <span class="type">guint</span></pre>
<p>Number of Channels.</p>
<p>Flags: Read / Write</p>
<p>Allowed values: &lt;= 255</p>
<p>Default value: 2</p>
</div>
<hr>
<div class="refsect2">
<a name="SpicePlaybackChannel--volume"></a><h3>The <code class="literal">“volume”</code> property</h3>
<pre class="programlisting">  “volume”                   <span class="type">gpointer</span></pre>
<p>Playback volume.</p>
<p>Flags: Read / Write</p>
</div>
</div>
<div class="refsect1">
<a name="SpicePlaybackChannel.signal-details"></a><h2>Signal Details</h2>
<div class="refsect2">
<a name="SpicePlaybackChannel-playback-data"></a><h3>The <code class="literal">“playback-data”</code> signal</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
user_function (<a class="link" href="SpicePlaybackChannel.html" title="Playback Channel"><span class="type">SpicePlaybackChannel</span></a> *channel,
               <span class="type">gpointer</span>              data,
               <span class="type">gint</span>                  data_size,
               <span class="type">gpointer</span>              user_data)</pre>
<p>Provide audio data to be played.</p>
<div class="refsect3">
<a name="id-1.2.3.8.14.2.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>channel</p></td>
<td class="parameter_description"><p>the <a class="link" href="SpicePlaybackChannel.html" title="Playback Channel"><span class="type">SpicePlaybackChannel</span></a> that emitted the signal</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>data</p></td>
<td class="parameter_description"><p>pointer to audio data</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>data_size</p></td>
<td class="parameter_description"><p>size in byte of <em class="parameter"><code>data</code></em>
</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>user_data</p></td>
<td class="parameter_description"><p>user data set when the signal handler was connected.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<p>Flags: Run First</p>
</div>
<hr>
<div class="refsect2">
<a name="SpicePlaybackChannel-playback-get-delay"></a><h3>The <code class="literal">“playback-get-delay”</code> signal</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
user_function (<a class="link" href="SpicePlaybackChannel.html" title="Playback Channel"><span class="type">SpicePlaybackChannel</span></a> *channel,
               <span class="type">gpointer</span>              user_data)</pre>
<p>Notify when the current playback delay is requested</p>
<div class="refsect3">
<a name="id-1.2.3.8.14.3.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>channel</p></td>
<td class="parameter_description"><p>the <a class="link" href="SpicePlaybackChannel.html" title="Playback Channel"><span class="type">SpicePlaybackChannel</span></a> that emitted the signal</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>user_data</p></td>
<td class="parameter_description"><p>user data set when the signal handler was connected.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<p>Flags: Run First</p>
</div>
<hr>
<div class="refsect2">
<a name="SpicePlaybackChannel-playback-start"></a><h3>The <code class="literal">“playback-start”</code> signal</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
user_function (<a class="link" href="SpicePlaybackChannel.html" title="Playback Channel"><span class="type">SpicePlaybackChannel</span></a> *channel,
               <span class="type">gint</span>                  format,
               <span class="type">gint</span>                  channels,
               <span class="type">gint</span>                  rate,
               <span class="type">gpointer</span>              user_data)</pre>
<p>Notify when the playback should start, and provide audio format
characteristics.</p>
<div class="refsect3">
<a name="id-1.2.3.8.14.4.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>channel</p></td>
<td class="parameter_description"><p>the <a class="link" href="SpicePlaybackChannel.html" title="Playback Channel"><span class="type">SpicePlaybackChannel</span></a> that emitted the signal</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>format</p></td>
<td class="parameter_description"><p>a <span class="type">SPICE_AUDIO_FMT</span></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>channels</p></td>
<td class="parameter_description"><p>number of channels</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>rate</p></td>
<td class="parameter_description"><p>audio rate</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>latency</p></td>
<td class="parameter_description"><p>minimum playback latency in ms</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>user_data</p></td>
<td class="parameter_description"><p>user data set when the signal handler was connected.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<p>Flags: Run First</p>
</div>
<hr>
<div class="refsect2">
<a name="SpicePlaybackChannel-playback-stop"></a><h3>The <code class="literal">“playback-stop”</code> signal</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
user_function (<a class="link" href="SpicePlaybackChannel.html" title="Playback Channel"><span class="type">SpicePlaybackChannel</span></a> *channel,
               <span class="type">gpointer</span>              user_data)</pre>
<p>Notify when the playback should stop.</p>
<div class="refsect3">
<a name="id-1.2.3.8.14.5.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>channel</p></td>
<td class="parameter_description"><p>the <a class="link" href="SpicePlaybackChannel.html" title="Playback Channel"><span class="type">SpicePlaybackChannel</span></a> that emitted the signal</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>user_data</p></td>
<td class="parameter_description"><p>user data set when the signal handler was connected.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<p>Flags: Run First</p>
</div>
</div>
<div class="refsect1">
<a name="SpicePlaybackChannel.see-also"></a><h2>See Also</h2>
<p><a class="link" href="SpiceChannel.html" title="Spice Channel"><span class="type">SpiceChannel</span></a>, and <a class="link" href="SpiceAudio.html" title="Spice Audio"><span class="type">SpiceAudio</span></a></p>
</div>
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